refactor: split monolith into 3 microservices (frontend, backend, discord-gateway)

- Extract services into services/{frontend,backend,discord-gateway}
- Create packages/shared/ for shared logger, errors, utils, types
- Setup Modular MVC pattern in backend (controller→service→repository)
- Setup event-driven architecture in discord-gateway with Redis pub/sub
- Move Docker files to infra/docker/ with per-service Dockerfiles
- Update docker-compose.yml to use Traefik-only routing (no port exposes)
- Update GitHub Actions deploy workflow for multi-service matrix build
- Fix all import paths and resolve type errors across all services
- All 3 services pass tsc --noEmit clean

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

services/frontend/src/shared/ui/button.tsx

@@ -0,0 +1,56 @@
+import { Slot } from "@radix-ui/react-slot";
+import type * as React from "react";
+import { cn } from "../lib/utils";
+
+type ButtonVariant =
+  | "default"
+  | "secondary"
+  | "destructive"
+  | "outline"
+  | "ghost";
+type ButtonSize = "default" | "sm" | "lg" | "icon";
+
+const variants: Record<ButtonVariant, string> = {
+  default: "bg-primary text-primary-foreground shadow hover:bg-primary/90",
+  secondary: "bg-secondary text-secondary-foreground hover:bg-secondary/80",
+  destructive:
+    "bg-destructive text-destructive-foreground hover:bg-destructive/90",
+  outline:
+    "border border-border bg-background hover:bg-accent hover:text-accent-foreground",
+  ghost: "hover:bg-accent hover:text-accent-foreground",
+};
+
+const sizes: Record<ButtonSize, string> = {
+  default: "h-10 px-4 py-2",
+  sm: "h-9 rounded-md px-3",
+  lg: "h-11 rounded-md px-8",
+  icon: "h-10 w-10",
+};
+
+export interface ButtonProps
+  extends React.ButtonHTMLAttributes<HTMLButtonElement> {
+  asChild?: boolean;
+  variant?: ButtonVariant;
+  size?: ButtonSize;
+}
+
+export function Button({
+  className,
+  variant = "default",
+  size = "default",
+  asChild = false,
+  ...props
+}: ButtonProps) {
+  const Comp = asChild ? Slot : "button";
+  return (
+    <Comp
+      className={cn(
+        "inline-flex items-center justify-center gap-2 whitespace-nowrap rounded-lg text-sm font-medium transition-colors focus-visible:outline-none focus-visible:ring-2 focus-visible:ring-ring disabled:pointer-events-none disabled:opacity-50",
+        variants[variant],
+        sizes[size],
+        className,
+      )}
+      {...props}
+    />
+  );
+}